Surface working apparatus



July 1, 1941.

P. A. FIsKE' SURFACE WORKING APPARATUS Filed Oct. '20, 1958 \llllTllll'llllllllll Patented July 1, 1941 NT OFFICE SURFACE WORKING APPARATUS Peder Andersen Fisker, Copenhagen, Denmark, assignor to A/ S Fisker & Nielsen, Copenhagen,

Denmark Application October 20, 1938, Serial No. 236,074 In Denmark October 22, 1937 3 Claims.

Surface working apparatus, particularly for the treatment of floor surfaces, such as polishing appliances, are known to contain one or several mechanically actuated working implements for example brushes.

Such machines are known with Working implements, especially brushes, having a rectilinear reciprocating motion, as well as with rotating working implements.

The aforementioned polishing apparatus containing brushes moving forwards and backwards yield an imperfect treatment of the polishing wax and a polishing effect inferior to that of polishing apparatus with rotating brushes.

Polishing apparatus with rotating brushes, however, are attended by the drawback that the individual bristles in the brush are actuated in mutually different tracks, as the bristles nearest to the axis of revolution are moved in small circles whereas the outer bristles are moved in large circles and at a -correspondingly greater speed. Rotating brushes have, on account of the centrifugal force, a tendency to eject impurities and the like from the brush and have moreover the drawback that all the bristles of the brush are constantly being bent in the same direction, opposing the direction of revolution. Furthermore rotating brushes have the drawback that the different areas of the track dealt with by the brushes are not uniformly treated.

By the known polishing machines with a single brush operating with a circular translatory motion the brush is driven by a single crank which moves the centre of the brush around in a circle. Other points on the brush, most frequently located in line with the centre of the brush, are guided by non-driving guide members in such a manner that the movements of these points also are restricted to circles. Thus all the bristles comprising the brush are moved in circles of equal magnitude. Since the brush is driven by a simple crank, this design suffers from the drawback that the brush may lock itself in the cranks dead centre positions.

This invention is directed towards the elimination of the aforesaid drawbacks in connection with surface working apparatus, primarily polishing or grinding appliances, and in which each of the working implements is operated with a rotating translatory motion, known per se, by multiple driving cranks. The working implements are preferably of elongated shape and are each operated with a circular translatory motion by multiple driving cranks, located in or in the vicinity of the longitudinal axis of the implements. As the working implements are actuated by multiple cranks, wedging is eliminated and the fact that the apparatus has two, or four, or more working implements arranged in pairs and actuated in opposition, it will be possible to construct the apparatus so that the forces deriving from the movements of the implements, especially centrifugal forces, will neutralize one another mutually in pairs.

The invention provides that the axles of revolution for the circular motions, i. e. the cranks axles, may be disposed with advantage in such a manner that they, when a pair of working implements are in the position of the closest proximity, are either wholly or mainly in the same vertical plane or surface as the outer circumference of the implements, for example their outer vertical side surface. This ensures that the extent of the rotating translatory motion of the implements from the inner position to the outer position will wholly or approximately correspond to the width of the implements.

As stated, the invention provides that the Working implements cooperating in pairs may advantageously be disposed and guided in the apparatus in such a manner that a pair of implements will mutually completely or almost completely eliminate the forces deriving from the movements, especially centrifugal forces.

This is obtained when the im'plements rotating translatory motions are made of equal size, the implements being at the same time arranged in opposing pairs and actuated in opposing directions.

The actuating cranks may with advantage be carried by the downwardly open chamber or flat, bell-shaped casing or frameof the machine, the cranks being arranged, preferably in ball bearings, in this chamber or casing.

The drawing shows an embodiment 'of the invention.

Fig. 1 shows a vertical section of the machine taken on the line A-A of Fig. "2,

Fig. 2 shows a half section plan taken on line B-B of Fig. 1. n V

Fig. 3 shows a plan view of the grinding or polishing implements with their driving crank members.

Fig. 4 shows a diagrammatic plan view of the transmission.

Fig. 5 shows, corresponding to Fig, 1, a vertical section through the machine in an amended embodiment.

In the embodiment shown the polishing machine consists of a casing I open downwardly and of approximately square shape, whose outer limits are indicated by a dotted line shown in Fig. 4; Onthe casings upper wall a motor case 2 is arranged, which may be integral with the l casing or attached to same.

The guide handle for the machine may be attached either to the casing l or to the motor case 2. The electric motor drives a gear 3, Figs. 1 and 4, which rotates two intermediate gears l2, Fig, 4, whose bosses carry smaller driving gears l3 revolving other gears 4, four in number. 1 connected each with its axle 5, Fig. 1, which'is The gears 4 are lodged .in bearings in the casing I and whose lower ends carry crank webs 6 preferably half 1 the width of a working implement terminating j in downwardly directed pins 1 which engage with corresponding bearings or guide holes in the of the working implements. The said points are 1 determined by the axes for the pins 1 and hence the normally rectangular brushes 8 will be moved in such a manner that the individual bristles will describe the same rotary motion. In this connection it is to be noted that this line forming thelongitudinal axis of the brush is always'par- I allelto a line intersecting the crank axes and j perpendicular thereto. that the machine is moved to work a track at Supposing for example right angles to the longitudinal axis of the workseen that the middle and widest part of this track will be treated quite evenly, whereas the outer edges of the track, in a width corresponding to twice the length of the crank webs 6, i. e.

a very narrow width since the crank webs 6 are on the drawing shown in exaggerated size, will appear uneven and non-uniformly treated so that it will be necessary by subsequent treatment to let these edge surfaces overlap.

The brushes 8 may of course be replaced by any other suitable working implements and driven if desired by more than two crank members. Fig. 5 shows, corresponding to Fig. 1, the machine in an embodiment where the working implement 8, instead of being a brush, is shaped as a polishing implement, the lower part of which consists of a suitable coating, e. g. a plate of felt 80. The working implement 8, 80 shown in Fig. 5 is moved by .four cranks, the machine having, besides the cranks 5, 6, 1, corresponding to those shown in Fig. 1, furthermore two cranks right into the corners of aroom and treat the fioor surface there, this because the circular motion of the bristles is small. i

Figs. 3 and 4 merely serve to illustrate the ad vantage of arranging the working implements in the apparatus in pairs and in such relation to one another that the forces deriving from. their movement, especially centrifugal forces will completely or nearly completely neutralize: one another, thus precluding a one-sided pull on the assembled machine.

It will be seen from Fig. 3 that the crank webs 6 are arranged opposed in respect to the two brushes whereas the direction of rotation is the same, as indicated by the arrows on the circles, hence the brushes will be subject to such opposed motion that the centrifugal forces are neutralized in that the upper brush seen in Fig. 3 will commence with a movement to the left and away from the other brush whereas the latter will commence with a movement to the right'and, similarly, away from'the said former brush.

I claim:

1. A machine for polishing or grinding floors and similar surfaces comprising a frame, at least one pair of oppositely arranged working implements movable in relation toithe frame, means for driving each of the implements including multiple driving crank members driving each implement, and arranged in such a manner that the longitudinal axis between the connecting points of the implement to the cranks remains parallel to a line intersecting the crank axes and perpendicular thereto.

2. A machine for polishing or grinding floors and similar surfaces comprising a frame, at least one pair of oppositely arranged working implements, of elongated shape, movable in relation to the frame, means for driving each of the implements with a rotating translatory motion, said driving means including multiple driving crank members driving" each implement, said crank members being arranged opposed in respect to the oppositely arranged implements and having the same direction of rotation, the pins of the crank members engaging said implements at points of the longitudinal axis of symmetry of the implements, said points being placed at a relativelylarge distance from one another.

. 3. A machine for polishing or grinding fioors and similar surfaces comprising a frame, at least one pair of oppositely arranged working implements, Of elongated shape, :movable in relation to the frame-means for driving each of the implethe same direction of rotation, the pins of the crank members engaging said implements at points of the longitudinal axis of symmetry of the implements, said points being placed at a relatively large. distance from one another, the distance between the, crank shaft axis and the crank pin axis being half the width of the implements.

" PEDER ANDERSEN FISKER. 

